Massachusetts-made “American Hustle” won big at the Screen Actors Guild Awards Saturday night in Los Angeles. Presenting Amy Adams, Jennifer Lawrence, Bradley Cooper, and the rest of the star-studded group with the Outstanding Performance by a Cast in a Motion Picture honor was Boston’s Ben Affleck, who was seen mingling during commercial breaks with Jared Leto and Tom Hanks. Ben also played it cool when actor Cuba Gooding Jr. rushed the stage at the end of the show, pushed him out of the way of the mike, and wished everyone “Happy MLK!” Local actors celebrated the ceremony at the SAG-AFTRA New England 3d annual SAG Awards Viewing Party. Attendees included actor A. G. Wilde, SAG-AFTRA New England executive director Susan Nelson, local board president Michele Proude, and board co-chairs Frank Cacciola and Chuck Slavin.